Don't be so hard on yourself PK - I do the same thing.
I've been doing my own version of Atkins now since last summer and have maintained my weight. Every once in a while I'll eat something that I know is not good for me but I make peace with myself because I know that 90 percent of the time I'm a good boy
Yesterday I ordered a thin-crust pizza from PapaJohns.com and am feeling exactly what you have described. I feel like I'm half asleep - haven't gotten enough rest - very lazy! Not sure what it is but it may very well be those carbs from the pizza - my body is just not used to that!
d*